1. Field of the Invention
The present invention relates to a tension device for use with a self-retracting lifeline.
2. Description of the Prior Art
Self-retracting lifelines are well known in the art of fall protection safety equipment for use by users performing tasks during which there is a risk a fall may occur. Self-retracting lifelines generally include a housing containing a drum around which a lifeline made of cable, rope, or webbing is wound. The drum is spring biased to pay out the lifeline as tension pulling the lifeline is applied and to retract any of the lifeline that has been unwound from the drum as the tension on the lifeline is reduced or released. In other words, the lifeline is paid out as the user moves away from the housing and the lifeline is retracted as the user moves toward the housing. The housing also includes a brake assembly for stopping rotation of the drum when the lifeline suddenly unwinds from the drum at a rate greater than a predetermined maximum angular velocity.
A self-retracting lifeline is typically connected to a support structure within the vicinity the user is performing the task, and the connecting end of the lifeline is typically connected to a safety harness worn by the user. The lifeline is easily drawn out of the self-retracting lifeline housing as the user moves away from the device, and the lifeline is automatically drawn back into the housing as the user moves toward the device. Should a fall occur, the brake assembly within the device is automatically engaged by a centrifugal clutch assembly, which stops the user's fall by gradually and quickly stopping the rotation of the drum. As the rotation of the drum is stopped, additional lifeline is prevented from being paid out of the housing to arrest the fall of the user.
During the fall, a ratcheting effect may occur. The term “ratcheting” in this context is a term used in the art to describe when the weight on the connecting end of the locked lifeline rebounds upward upon impact. The upward rebound releases the brake assembly thereby allowing the lifeline to be retracted and paid out, and the user will fall further until the brake assembly again stops the rotation of the drum. This ratcheting effect may occur several times during a fall.
A shock absorber may be operatively connected proximate the connecting end of the lifeline to dissipate the force should a fall occur. Once the lifeline of the self-retracting lifeline is locked by the brake assembly, the shock absorber reduces the force of the fall on the user. A typical shock absorber utilizes a tearing action to absorb the force as the fall of the user is arrested. Although the shock absorber reduces the force of the fall, the ratcheting affect may still occur during a fall.